<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="d3.min.js"></script>
</head>
<body>
<script>
    var width = 400;
    var height = 400;
    var svg = d3.select('body')
        .append('svg')
        .attr('width',width)
        .attr('height',height);
    svg.append('circle')
        .attr('cx','50px')//圆形横坐标
        .attr('cy','50px')//圆形纵坐标
        .attr('r','50px')//圆形半径
        .attr('fill','red');//填充颜色
</script>
</body>
</html>